Why Do Smartphones Always Know When You're Tired?

Smartphones know when you're tired because they have sensors that can tell how much light is coming into your room and whether your phone is moving. When the light gets dark and the phone stays still, it thinks you might be sleeping, just like a nightlight knows when to turn on.

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Examples

Your phone turns on a nightlight when it gets dark, like it knows you're going to sleep.
Your phone sends a 'Goodnight' message when it thinks you've fallen asleep.
It notices that your phone isn’t moving and the room is getting darker.

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Categories: Technology · smartphone· technology· sleep tracking· mobile apps· health tech